/*
 * Copyright 2015 The Netty Project
 *
 * The Netty Project licenses this file to you under the Apache License,
 * version 2.0 (the "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at:
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */

package io.netty.resolver;

import io.netty.util.concurrent.EventExecutor;
import io.netty.util.concurrent.Promise;
import io.netty.util.internal.SocketUtils;
import io.netty.util.internal.UnstableApi;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.Arrays;
import java.util.List;

/**
 * A {@link InetNameResolver} that resolves using JDK's built-in domain name lookup mechanism. Note
 * that this resolver performs a blocking name lookup from the caller thread.
 */
@UnstableApi
public class DefaultNameResolver extends InetNameResolver {

  public DefaultNameResolver(EventExecutor executor) {
    super(executor);
  }

  @Override
  protected void doResolve(String inetHost, Promise<InetAddress> promise) throws Exception {
    try {
      promise.setSuccess(SocketUtils.addressByName(inetHost));
    } catch (UnknownHostException e) {
      promise.setFailure(e);
    }
  }

  @Override
  protected void doResolveAll(String inetHost, Promise<List<InetAddress>> promise)
      throws Exception {
    try {
      promise.setSuccess(Arrays.asList(SocketUtils.allAddressesByName(inetHost)));
    } catch (UnknownHostException e) {
      promise.setFailure(e);
    }
  }
}
